"But ye shall receive power, after that the Holy Spirit is come upon you" (Acts 1:8)
Some good Christians have misread this text and have assumed that Christ told His disciples that they were to receive the Holy Spirit and power, the power to come after the coming of the Spirit. But the truth is that Christ taught not the coming of the Holy Spirit as power; the power and the Spirit are the same.
Our Lord before His ascension said to His disciples, "Tarry ye in the city of Jerusalem, until ye be endued with power from on high" (Luke 24:49). That word "until" is a time-word; it indicates a point in relation to which everything is either before or after.
So the experience of those disciples could be stated like this: Up to that point they had not received the power; at that point they "did" receive the power; after that point they "had" received the power. That power, still active in the Church, has enabled her to exist for nearly twenty centuries.
Christianity takes for granted the absence of any self-help and offers a power which is nothing less than the power of God.
~A. W. Tozer~